Br?nsted-Lewis双酸性离子液体催化合成对苯二甲酸二(二乙二醇丁醚)酯

Synthesis of Di(2-(2-butoxyethoxy) ethanol) Terephthalate Catalyzed by Br?nsted-Lewis Acidic Ionic Liquid

制备了具有不同SnCl2摩尔分数的Br?nsted-Lewis双酸性离子液体3-(1-吡啶基)丙磺酸-氯化亚锡离子液体([3-(1-Py)-(CH2)3-SO3H]Cl-xSnCl2),x为Lewis所占的摩尔分数。用吡啶探针红外光谱作为表征手段,比较了不同x值催化剂的酸性强度变化,并将其应用于对苯二甲酸二(二乙二醇丁醚)酯的合成反应。考察了x值、原料配比、催化剂用量、带水剂用量、反应时间对酯化率的影响,并对精制产品用1HNMR和GC-MS进行结构表征。结果表明,当x=0.5时,该离子液体的催化活性最高。以[3-(1-Py)-(CH2)3-SO3H]Cl-0.5SnCl2为催化剂,对苯二甲酸(PTA)和二乙二醇丁醚(DGBE)的摩尔比n(DGBE)∶n(PTA)=2.3∶1,催化剂用量为4.0%(以PTA质量计),带水剂正丁醚用量为60.0%(以PTA质量计),反应时间为2.5h,搅拌转速300r/min时,产品的酯化率高达99.43%,催化剂催化活性在重复利用5次后才开始下降。

Brcnsted-Lewis acidic ionic liquid [ 3-（1-Py）-（ CH2 ）3-SO3H] CI-xSnC12 with different mole fractions of SnC12 was prepared （where x is the mole fractions of the Lewis acid）. The acidity of the group was characterized and compared to each other by means of FTIR in virtue of pyridine molecular probe, and the dual acidic ionic liquids were then employed in the synthesis reaction of di （2-（ 2- butoxyethoxy） ethanol） terephthalate. The influences of catalyst type and amount, ratio of reactants, dosage of water-entrainer, reaction time were investigated. In addition, the structure of the re.fined target product was characterized by means of 1HNMR and GC-MS. The results show that [ 3-（1-Py） -（ CH2 ） 3- SO3 H ] El-0. 5SnC12 had the highest catalytic activity. With [ 3-（1-Py）-（ CH2 ）3-SO3 H ~ C1-0. 5SnC12 as catalyst, the optimal reaction conditions were as follows ： n （ DGBE ） ： n （PTA） = 2. 3 ： 1, catalyst （4.0% of mass of PTA） ,water-entrainer （60. 0% of mass of PTA） ,reaction time （2. 5 h） and the speed of stirring was 300 r/min. Under such conditions, the activity became weaker after five cycles of use. esterification rate was 99.43%. The catalytic